Finding the Fourth Proportional to 1,759.77, 2,431.37 and 1,389.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,759.77 : 2,431.37 = 1,389.57 : x
2. Step 2: Convert to fraction form
   1,759.77/2,431.37 = 1,389.57/x
3. Step 3: Cross multiply
   1,759.77x = 2,431.37 × 1,389.57
4. Step 4: Simplify right side
   1,759.77x = 3,378,551.86
5. Step 5: Solve for x
   x = 3,378,551.86/1,759.77
6. Step 6: Final answer
   x = 1,919.88